This invention relates to dust suppression and more particularly to the use of an aqueous solution of polyethylene oxide for the purpose of dust suppression.
Dust suppression connotes the prevention or reduction of the extent to which finely particulate solid matter becomes suspended in a gas, usually air. In this situation, the finely particulate solid matter can either already be in existence or being produced as a result of various mechanical operations such as grinding, milling, cutting, pounding, explosion, and the like. Common industrial sources of dust are open operations, leaks and spills, storage and disposal, and poor housekeeping. Transportation, handling, and storage are all areas wherein a great amount of coal dust is created.
Dust created in industrial situations is a major cause of air pollution. Everyone is aware that the dust which is created in coal mining operations is considered to be a major cause of pneumoconiosis, more commonly known as black lung disease. Since the dust is confined within a small air space in coal mining operations, dust explosions are a serious hazard. The present invention is intended to provide one method by which the foregoing undesirable results may be avoided.
In both industrial and coal mining applications, there already exist both mechanical and chemical methods for preventing dust or fine particulate matter from becoming airborne. Ventilation and/or the use of exhaust fans are used in both industrial and mining applications. Furthermore, water is commonly used to prevent dust particles from becoming airborne by keeping them wet and there are a number of aqueous solutions (of surfactants, etc.) which are also used for this purpose. U.S. Pat. Nos. 3,690,727, issued to Degginger on Sept. 12, 1972, and 4,136,050, issued to Brehm on Jan. 23, 1979 describe such aqueous solutions. Aqueous foam compositions have also been used to suppress dust. This method was initially studied in British coal mines and U.S. Pat. No. 3,954,662, issued to Salyer, Schwendeman, and Shih-ming Sun on May 4, 1976, describes one such aqueous foam composition.
As stated above, the present invention contemplates the use of an aqueous solution of polyethylene oxide to achieve the advantageous results described herein. U.S. Pat. Nos. 2,538,199 issued to Jefferson and Stigger on Jan. 16, 1951, and 2,620,044 issued to Fine and Trowbridge on Dec. 2, 1952, describe dust adhesives for gas filters. These compositions include, among other ingredients, polyethylene ethers of sorbitan mono tall oil ethers, alkyl phenols, glycerol, diethylene glycol, sorbitol, glucose, diglycerol, sucrose, and others as wetting agents. These compounds appear to be somewhat similar structurally to the polyethylene oxide of the present invention, but as ethers they are quite obviously chemically distinct therefrom. U.S. Pat. No. 4,136,050, issued to Brehm on Jan. 23, 1979, describes a method for increasing the wettability of dust particles by treating them with an aqueous solution of octylphenoxy polyethoxy ethanol and a copolymer of ethylene oxide and propylene oxide. This patent discloses only that the composition is useful in liquid form. The advantages of dust suppression are also achieved with the present invention after the water has evaporated. The polyethylene oxide acts as a dust suppressant after the composition has dried on the coal or other dust-producing material to which it has been applied.